Fuel pump lever with sliding shoe



April 8, 1958 A. c. KORTE 2,829,541

FUEL PUMP LEVER WITH SLIDING SHOE Filed Nov. 3, 1952 2 Sheets-Sheet 1INVENTOR.

ALFRED C. KORTE ZZ /K M ATTORNEY April 8, 1958 A. c. KORTE 2,829,541

FUEL PUMP LEVER WITH SLIDING SHOE Filed Nov. 5, 1952 2 Sheets-Sheet 2INVENTOR. ALFEQED C. E 'KORTE BY ATTORNEY United States Patent FUEL PUMPLEVER WITH SLIDING SHOE Alfred C. Korte, St. Louis, Mo., assiguor, bymesne assignments, to ACE Industries, Incorporated, New York, N. Y., acorporation of New Jersey Application November 3, 1952, Serial No.318,454

Claims. (Cl. 74-569) This invention relates to contact shoes foreccentric and follower mechanisms and consists particularly in a contactshoe having an arcuate contact face and means for maintaining thearcuate face in constant registry with the eccentric surface.

Fuel pumps and vacuum booster pumps of the type used on automotivevehicles are commonly actuated by a lever resiliently urged in contactat one end with an eccentric on the engine camshaft. In the conventionalmechanism, a flat surface of the follower lever makes a line contactwith the face of the eccentric at the point of tangency. As a result ofthe small contact surface and of the extremely. hard services to whichmechanisms of this type are put, wear on the lever is severe, so thatthe service life of the lever is relatively short.

Accordingly, it is an object of this invention to provide a novel meansfor reducing wear between the eccen tric and the follower lever, so asto prolong the service life of the mechanism.

Another object is to provide an arcuate contact shoe for eccentric andfollower mechanisms with means for automatically maintaining the entirecontact face of the shoe in engagement with the eccentric surface,regardless of the rotational position of the eccentric or of slightnon-parallelism between the axis of the eccentric and the fulcrum of thefollower lever.

These objects are achieved by interposing between the eccentric and thelever 21 contact shoe having a concave arcuate upper surface of the sameradius as the eccentric for registry with the eccentric and by formingthe undersnrface of the shoe with a longitudinal semi-cylindrical cavityand the upper surface of the lever of semi-cylindrical cross-section forregistry with the shoe, so as to permit not only slidable movement ofthe shoe along the longitudinal axis of the lever, but also slightrotary movement of the shoe about the lever.

Additional objects and advantages will appear from the specificationwhen read with the accompanying drawing in which:

Fig. 1 is an elevation view, partially sectionalized, of an automotivefuel pump embodying the invention.

Fig. 2 is an enlarged vertical sectional view of the shoe and leverillustrated in Fig. 1, showing mean and extreme positions of the shoe.

Fig. 3 is an end view of the shoe.

Fig. 4 is a perspective view of the shoe.

Fig. 5 is an elevation view, partially sectionalized, of a modified formof shoe and lever.

Fig. 6 is a transverse vertical sectional view of the modification ofFig. 5 along the line 66 of Fig. 5.

Fig. 7 is a transverse vertical sectional view similar to Fig. 6, butshowing tilted positions of the shoe.

Fig. 8 is a perspective view of the shoe.

The automotive fuel pump illustrated in Fig. 1 is of the Carter type nowin wide use, and includes a body portion 5 which contains an operatingdiaphragm, valves, and vapor dome spaces, all as disclosed in acopending application, Serial No. 728,979, filed February 17, 1947,

now Patent No. 2,625,114 issued January 14, 1953, in the name of IrvenE. Coffey. Secured to the upper part of body 5 is a right angle leverhousing 6 into which projects diaphragm stem 7 through flexible seal 8.Diaphragm spring 9 constantly urges the diaphragm into the dischargedirection, that is, downwardly. An operating lever 10 of channelcross-section is pivoted at 11 to the walls of the lever housing, andhas a bifurcated end 12 which underlies an abutment washer 13 at the endof stem 7.

This application describes an improvement in the slid-' ing shoe for apump actuating arm disclosed in a copending application by J. L. Edelen,now Patent No. 2,654,266, dated October 6, 1953.

According to the present invention, the outer end of the lever is ofU-shaped channel cross-section, the upper surface 15 being ofsemi-cylindrical section. A contact shoe 17 having a longitudinallyextending semi-cylindrical recess 18 in its under-surface, is slidablymounted on the U-shaped end of the lever 10. For retaining shoe 17 onthe lever and for limiting rotation of the shoe about the longitudinalaxis of the lever, the sides 19 of semicylindrical recess 18 areextended downwardly at a slight divergency with each other and terminatein inwardly extending retaining flanges 21, which are adapted to engagethe lower edges of the flanges of lever 10 when the shoe reaches itslimit of rotation in either direction.

Sides 19 and flanges 21 constitute, in effect, stops concentricallyarranged with respect to bearing 18 limiting rotational movement of theshoe; this is particularly useful in installing fuel pumps on engines,because the shoe is thus retained upright at all times, with its contactface toward the eccentric. In order to prevent the shoe from sliding offthe end of the lever, tip 22 of the lever is bent upwardly as shown inthe drawing for engagement with the adjacent end of the shoe. The

upper surface of the shoe 24 is of concave arcuate form for engagementwith the surface of eccentric cam 25 which is mounted on and driven bycamshaft 27. A coiled spring 28 seated at 29 in the lever housing. andbearing at its other end against the undersurface of the leverconstantly urges the shoe against the cam.

Operation of the device is as follows: As eccentric 24 of the shoe whichis in wiping contact with the cam surface, and the lower large bearingsurface 18 of the shoe and 15 of the lever which are in slidablerelation with each other. The semi-cylindrical undersurface of the shoeand the semi-cylindrical upper surface of the lever permit sufiicientrotation of the shoe about the longitudinal axis of the lever to insurethat the entire upper surface of the shoe will be at all times incontact with the surface of the cam.

A modified form of shoe and lever is shown in Figs. 5-8. In thismodification the numeral 32 indicates a lever arranged for pivotalmounting at 11 in lever housing 6 of the pump illustrated in Fig. 1. Theouter end portion 34 of lever 32 is cylindrical, and is adapted toslidably mount shoe 36. Contact shoe 36 is provided with a concave,arcuate upper contact surface 37, the radius of this surface being equalto that of the eccen-.

Patented Apr. 8, s

Wear on the cam and follower mechanism is minimized due to the largeupper arcuate bearing surface tric 25 in order to permit registrybetween a large area of each of the two surfaces. Shoe 36 is providedwith a longitudinal, cylindrical opening 39 to permit rotatable, as wellas slidable, mounting of the shoe on cylindrical portion 34 of thelever, as shown in Fig. 5. To limit longitudinal movernent of the shoeon the lever,

and thus to prevent its coming off the lever at the outer end or wedgingagainst the thickened portion of the lever adjacent the fulcrum, a pairof raised bosses 41 are formed on the surface of the lever at each endof the shoes permissible travel. In order to hold the shoein asubstantially upright position during installation of the pump on theengine, and at the same time to permit such slight rotation of the shoeabout the longitudinal axis of the lever as may be desirable for keepingthe contact face of the shoe at all times in registry with the eccentricsurface, an additional fin-shaped boss 43 is formed on the bottomsurface of the lever intermediate the bosses 41, and the bottom ofcylindrical opening 39 in the shoe is provided with a longitudinally extending groove 45 somewhat wider than boss 43 and are equally spacedfrom a central plane axially of hearing 39. Thus, slight rotation of theshoe is permitted, its magnitude being limited by the engagement ofeither of the concentrically arranged sides of groove 45 with thecorresponding side of boss 43, as best seen in Fig. 7.

Operation of the device of Figs. 5-8 is as follows: As the eccentricrotates on the camshaft, shoe 36 slides along the cylindrical portion 34of the lever so that its contact surface 37 always stays in contact withthe eccentric surface, wear on the mechanism being minimized by thelarge areas of contact between the shoe and the eccentric and betweenthe shoe and the lever. The maintenance of a constant large area ofcontact between the shoe and the eccentric is further insured in thisform of my invention by the rotatable mounting of the shoe on the lever,which permits the shoe to compensate for any non-parallelism existingbetween the surface of the eccentric and the fulcrum of the lever.

It will be understood that the forms described and illustrated hereinare but the preferred embodiments of my invention, and that exclusiveuse is contemplated of all modifications coming within the scope of theappended claims as will occur to those skilled in the art.

I claim:

1. In a mechanism for driving a fuel pump, a pump housing, a leverpivotally mounted on said housing and having an outwardly projectingarm, a shoe on said arm, a rotatable eccentric engaging said shoe topivot said levet, and means providing linear sliding movement of saidshoe longitudinally of said arm and pivotal adjust ment of said shoetransversely of said arm during sliding movement.

'2; In a. mechanism for driving a fuel pump, a pump housing, a leverpivotally mounted on said housing and having an outwardly projectingarm, a shoe on-said arm, a rotatable eccentric engaging said shoe topivot said lever, and means providing linear sliding movement of 4 saidshoe longitudinally of said arm and pivotal adjustment of said shoetransversely of said arm, said eccentric having a convex cylindricalworking surface conforming to and engaging a semi-cylindrical concavesurface on said shoe, the axis of rotation of said eccentric extendingtransversely of the arm.

3. In a mechanism for driving a fuel pump, a pump housing, a leverpivotally mounted on said housing and having an outwardly projectingarm, a shoe on said arm, a rotatable eccentric engaging said shoe topivot said lever, and means providing linear sliding movement of saidshoe longitudinally of said arm and pivotal adjustment of said shoetransversely of said arm, said armbeing of channel section and having anarcuate convex surface engaging an arcuate concave surface on said shoe.

4. A mechanism according to claim 1 wherein, said shoe is provided witha cylindrical bore, and said arm is of circular section and extendsthrough said bore.

5. In a mechanism for driving a fuel pump, a pump housing, a leverpivotally mounted on said housing and having an outwardly projectingarm, said arm including an elongated portion formed with a transverselyarcuate convex upper bearing surface, means yieldably resisting pivotalmovement of said arm, a shoe having a lower transversely concave bearingsurface mounted on the upper convex bearing surface of said arm fortransverse movement and longitudinal sliding movement relative to saidarm, and arotatable eccentric engaging said shoe to pivot said lever.

References Cited in the file of this patent UNITED STATES PATENTS774,496 Rivett Nov- 1 4 831,912 Wadsworth Sept. 25, 1906 1,103,038Clemans July 14, 1914 1,372,408 Dyson Mar. 22, 1921 1,658,318 WinemanFeb. 7, 1928 1,682,924 Michell Sept. 4, 1928 1,729,448 Michell Sept. 24,1929 2,093,554 Foehrenbach Sept. 21, 1937 2,183,061 Bochmann Dec. 12,1939 2,207,332 Paxton July 9, 1940 2,209,479 Spencer July 30, 19402,226,985 Spencer Dec. 31, 1940 2,335,988 Anderson Dec. 7, 19432,404,231 Harper July 16, 1946 2,415,623 Brooks et al. Feb. 11, 19472,448,989 Leake Sept. 7, 1948 2,611,292 Chandler Sept. 23, 19522,654,266 Edelen Oct. 6, 1953 2,733,618 Johnson Feb. 7, 1956 FOREIGNPATENTS 316,886 Germany Dec. 11, 1919 432,504 France Oct. 6, 1911605,242 Great Britain July 19, 1948

